v,11JL°tur;9^iarm-}        Determination  of  Morphine.  697 
Total  acid  used  =17.00  'Cc. 
Acid  equivalent  to  the  alkali  =  7.10  Cc. 
Acid  equivalent  to  the  morphine  =  9.90  Cc. 
Weight  of  morphine  extracted  =  0.2970  Gm. 
Loss  of  morphine  =  0.0030  Gm,  equivalent  to  0.1  Cc.  of  standard 
acid. 
After  being  extracted  as  above  described,  the  aqueous  layer  was 
slightly  acidified  and  evaporated  to  small  volume.  Tested  for  the 
presence  of  morphine  by  iodic  acid,  by  bismuth  potassium  iodide 
and  by  iodine  solution,  this  concentrate  gave  in  each  case  a  negative 
result. 
Experiment  6. — Pure  morphine  was-  dissolved  in  standard  acid. 
The  solution  was  then  titrated  with  standard  sodium  hydroxide 
solution. 
Total  acid  used  =25.00  Cc. 
Acid  equivalent  to  the  alkali  =  15.00  Cc. 
Acid  equivalent  to  the  morphine  =  10.00  Cc. 
The  titrated  solution  was  faintly  acidified  with  hydrochloric  acid, 
evaporated  almost  to  dryness  on  the  water  bath  and  transferred  to 
a  separating  funnel,  washing  in  with  10  Cc.  of  water  and  3  Cc.  of 
alcohol.  Enough  sodium  hydrogen  carbonate  (a  saturated  aqueous 
solution)  was  added  to  make  the  whole  distinctly  but  slightly  alka- 
line.   The  morphine  was  then  extracted  exactly  as  in  Experiment  5. 
Titration  of  the  residue  produced  the  result  which  follows. 
Total  acid  used  =  25.00  Cc. 
Acid  equivalent  to  the  alkali  =  15:05  Cc. 
Acid  equivalent  to  the  morphine  =  9.95  Cc. 
Morphine  apparently  lost  in  the  extraction  was  therefore  0.0015  Gm. 
(=0.05  Cc.  acid)  which  is  within  the  limit  of  observational  error. 
For  complete  extraction  of  morphine  by  this  method  the  initial 
volume  of  the  aqueous  layer  should  not  exceed  the  volume  of 
chloroform-alcohol  taken  for  each  extraction.  When  the  former  was 
40  Cc.  and  the  latter  25  Cc,  it  was  found  that  four  extractions  left 
0.018  Gm.  (6  per  cent.)  of  the  base  in  the  aqueous  layer. 
When  0.2727  Gm.  of  morphine  was  in  50  Cc.  of  solution  it  was 
completely  extracted  by  shaking  four  times  with  50  Cc.  of  chlo- 
roform-alcohol mixture. 
